Chapter 3 - Electrical Terminology Flashcards
EMF (electromotive force) is also known as?
Volt.
In order for current to flow, there must be voltage and a___
Closed circuit.
Define resistance.
An opposition to the free flow of current.
Define power.
The rate at which work is being done. (measured in current)
Work is a force applied over a distance. If twice the force is applied over half the distance, is the amount of work done the same?
Yes.
If power is voltage times current, is half the voltage and twice the current the same amount of power?
Yes.
True or false: Electricity is a form of energy.
True.
Energy is power times ____.
Energy is power times time.
According to the law of conservation of energy, energy can neither be ______.
Created nor destroyed.
Can current flow in a circuit without voltage?
No.
The ampere is a unit of measure of ____?
Current.
Define a volt.
The potential difference across a 1 watt load with a current of 1 amp.
Define an ohm.
The amount of resistance that will produce voltage drop of 1 volt given 1 amp of current.
What is the inverse of resistance?
Conductivity.
What does voltage do?
Provides force that causes electrons to flow through a conductor.
What is current?
The flow of electrons.
Resistance is increased with:
Length, increasing temperature, decreasing cross-sectional diameter of a conductor.
Resistance in a circuit affects:
Applied voltage, amount of current that flows, amount of energy used.
Power is the product of _____.
Voltage and current at any instant in time.
What is energy?
Power over time.
Is energy the same as power?
No. Electricity is a form of energy, but energy is not the same as power.
Define an amp.
The amount of force produced by two current-carrying conductors.
What determines the category of a meter?
Intended use, ability to withstand transient over voltages, distance to power source.
What is a category IV meter used for?
Portable power generators, electrical meters, primary side of feeder transformers, primary overcurrent protection equipment, outdoor conductors.
